A keyboard is an input device which looks like a typewriter and is configured of Korean character keys, alphabetic keys, numeric keys, special character (non-character) keys and twelve function keys. Generally, the keyboard cannot be used standalone and may confirm, edit and modify input content in pair with an image display device (a monitor).
The operating principle of a keyboard is divided into an electronic type and a mechanical type according to the method of flowing electrical current. The electronic type is a method of grasping a pressed state of a key by measuring an amount of electric charges using a circuit connected under the key as the key is pressed. The mechanical type is a method of grasping a pressed state of a key by detecting whether electrical current flows as two metal plates under the key are attached or detached as the key is pressed.
A position of a key grasped from the keyboard is converted into a keyboard scan code through BIOS, recorded in a buffer, transmitted to a system and processed in the system.
Although the number of keys on a keyboard is 83 or 84 in the early stage, it has gradually increased to 101, 103 and 106 keys as the functions are expanded. A generally used keyboard is for Windows and has 106 keys in most cases. The keyboard is divided into a 2-set Korean keyboard, a 3-set Korean keyboard, an English QWERTY keyboard and an English Dvorak keyboard according to the form of arranging the keys.
The English QWERTY keyboard is a standard keyboard of the United States, which is named since the alphabetic characters in the first row below the numeric keys are arranged in order of Q, W, E, R, T and Y from the left.
The English Dvorak keyboard is a keyboard adopted as a second standard by the ANSI, in which frequently used keys are arranged at the center of the keyboard to improve input speed.
The keyboard has various non-character keys such as a Ctrl key, an Alt key, a Shift key, an Enter key, a Tab key and the like, in addition to the character keys. Since these non-character keys are used to change the original meaning of a key, to control operation of a program or to move text or a cursor on a monitor, they are referred to as special keys.
Smart devices such as smart phones, tablet PCs and the like are spotlighted recently, and although the smart devices adopt a text input method in the early stage using a touch screen, instead of a keypad, to show various information to a user, there is a problem of inputting an error by touching an adjacent key in the process of displaying a keyboard in a limited space and inputting text by the user by pressing keys one by one using a finger.
Particularly, the method of inputting text using a touch screen of a smart device invites inconvenience in using the smart device while doing a work in an office or the like, not in a state of moving with the smart phone.